Children and adolescents can suffer from a variety of conditions associated with abnormalities in behavior and cognitive brain function. This project will create a tool for assessing cognitive brain function in juvenile populations that is robust, repeatable, and free of cultural bias. It builds on innovative methods we have developed that combine task-related measures of response speed and accuracy with concomitant monitoring of neurophysiologic signals. We have so far established that such combined measures improve sensitivity for detecting the neurocognitive effects of medical treatments, help to separate effects due to variations in level of effort or alertness from those related to the regulation of attention and memory, are stable over time in the absence of developmental or medical changes, and are highly correlated with conventional measures of cognitive ability. However these methods are currently limited to comparing a patient's post-treatment test results to that patient's own pre-treatment baseline. This limitation is analogous to a thermometer that only tells whether a patient's temperature changed from the last measurement or an automobile whose speedometer shows change in miles per hour from yesterday. The current project is concerned with overcoming this limitation by utilizing age-matched reference groups to derive assessments of the neural correlates of sustained attention and working memory that can be used to gauge whether a child's neurocognitive ability is within normal bounds and whether it follows a typically maturational progression when tested repeatedly over an extended period. This will be accomplished in Phase II by collecting and analyzing a normative database that will enable comparison of a child's behavioral and neural responses with those of healthy age-matched peers, as well as comparison of any changes observed over time to those which would be expected as a result of normal maturational processes. The improved measures will then be validated by application to data collected from children with several clinical disorders that affect neurocognitive function including sleep disorders, epilepsy, ADHD and mild traumatic head injury. The resulting method will be embodied in a first-of-its-kind, highly automated Children's Neurophysiologic Cognitive Assessment Test (CNCAT). Because there is a large population of children that could benefit from assessment with the CNCAT in conjunction with their medical care, the test has a promising commercial future. [unreadable] [unreadable]